1. Field of the Invention
The present invention relates to valves. More particularly, the present invention relates to valves useful with hydrants such as fire hydrants which prevent water loss, in case of accidental breaking away of the hydrant, and backflow into the water system.
2. Description of the Related Art
Hydrants such as fire hydrants are particularly susceptible to being broken away from their water supply system due to vehicle collisions due to their proximity to city streets as commonly installed. Upon the hydrant breaking away, a large flow of water would be released from the water system if left unchecked. In a wet barrel hydrant, useful in mild climates, the hydrant is kept at water system pressure. It is known to provide a breakaway connection with a water system riser such as a breakaway flange ring or a breakaway riser, allowing the hydrant to break away from the water system riser upon collision, thus minimizing the overall damage to the water system. It is also known to provide valves, such as flap valves between the breakaway flange or breakaway riser and the water system riser which stop the uncontrolled flow of water from the system upon collision. In some cases, backflow from the hydrant or broken off flange or breakaway riser can take place, allowing contaminated water to enter the water supply system. It would be desirable to provide a valve which is simple in design and mountable between a water system riser and a hydrant having a breakaway flange ring or riser, the valve acting as a stop valve to prevent uncontrolled flow of system water from the broken hydrant system while acting as a check valve to prevent backflow of contaminated water into the water system riser.
U.S. Patent Publication No. 2003/0150486 A1, published Aug. 14, 2003, for Liebert, describes a breakaway safety shut-off valve for use with a tank for flammable liquids or dangerous chemicals having an upwardly spring-biased ball which is separated from a shutoff seat by arm segments to maintain the ball valve in an open position during normal use of the safety valve. Upon the breaking away of the safety valve at a weakened break-off point such as by accident or sabotage, the arm segments disengage an annular shoulder, allowing the spring-biased ball to shut against the seat, thereby closing the broken valve.
U.S. Pat. No. 22,927, issued Feb. 15, 1859, to Bartholomew, describes a hydrant with a lower ball valve in a curved standpipe.
U.S. Pat. No. 208,072, issued Sep. 17, 1878, describes a hydrant having a ball valve W.
U.S. Pat. No. 349,230, issued Sep. 14, 1886, to Mead, describes a hydrant having a supplemental twist-open valve for allowing system water to enter a hydrant from a riser.
U.S. Pat. No. 4,127,142, issued Nov. 28, 1978, to Snider, describes a flap type check valve connected between a riser pipe and wet barrel hydrant, the connection with the hydrant being a breakaway flange connection. Upon rupture of a breakaway flange connection, the check valve is allowed to close, stopping uncontrolled flow of water from the broken hydrant system.
U.S. Pat. No. 5,941,268, issued Aug. 24, 1999, to Ross, Jr., describes a knock-off tank safety valve employing a spring-loaded mushroom valve which closes when the safety valve is broken away.
European Patent No. EP1010824, published Jun. 21, 2000, describes a hydrant having a bulbous ball check valve located between the hydrant and a riser pipe having a vertically traveling ball guided by guide rods between upper and lower seats.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, a hydrant knock-off flow stop valve solving the aforementioned problems is desired.